Tool/software:
Dear Engineers,
I have designed an transimpedance amplifier for an ultrasound transducer as follows:
Ultrasound transducer feature: C=1nF, R=1.2K, working frequency between 2-3 MHz
When the transducer is connected everything works nicely, as soon as the transducer is disconnected as follows:
the circuit start to oscillate. I assume the reason is that OPA838 is not unity gain stable and when there is no capacitance on the inverting input, we can not provide the minimum noise gain for it.
My question is how I can adjust my circuit, even if there is no senor connected, the circuit remains stable, but I expect after I adjust the circuit, I still get the same bandwidths and amplification as before. What change do you suggest? (I don not want to change OPA838)
Regards,
